The new “hydromulch” spray is being studied by Greg Holt and Mike Buser, agricultural engineers with the USDA-ARS Cotton Production and Processing Research Unit in Lubbock, and Daren Harmel and Ken Potter, agricultural engineer and soil scientist with the ARS Grassland Soil and Water Research Laboratory in Temple, Texas.
Field testing will take place at Summit Seed, Inc., in Manteno, Ill.
A slurry mixture that is sprayed onto the ground for land reclamation, erosion control and other purposes, hydromulch typically contains green-dyed paper, wood or straw in a slurry mixture with water and grass seed. The slurry helps grass seed stick and stay in place and provides a moist and nutritious mulch for germination.
The test hydromulches will have ryegrass seed in them and will be dyed red, green or brown to distinguish between those made with wastes from different cotton gin processes and regions.
The researchers will compare the test hydromulches with three conventional ones, looking at factors such as seed germination, costs and erosion control.
The waste is held together by a low-cost process called COBY, for Cotton Byproducts. The process, invented by Greg Holt and Mike Buser, uses a hot, gelatinized starch solution that acts as a glue and as a lubricant to smooth the mixture's flow through extrusion equipment.
The scientists see this as another way to use waste material that cotton gins would otherwise have to pay to have removed. They estimate those costs to be $4 million to $6 million annually.
The cotton-waste mixture has also been made into pellets and tested in pellet-burning stoves and as fertilizer and cattle feed. In a test with 162 heifers, cattle gained more weight on less feed. Summit Seed is also testing a dry mixture as a bedding mulch for landscaping use.